1. Field of the Invention
This invention relates to a digital camera. More particularly, this invention relates to a digital camera that is capable of producing and recording printing information, e.g., numbers of prints to be produced, of photographed images.
2. Description of Related Art
Currently, a digital image photographed by a digital camera is generally recorded in a recording medium (a removable medium) such as a detachable memory card and a magnetic disk. The image recorded in the recording medium is not only displayed on a monitor but also printed with a personal printer for domestic use or the like. In recent years, the image can be printed at a laboratory in response to an order in the same way as that on a film.
In the future, the images are expected to be printed more with the personal printer and at the laboratory with the spread of digital cameras. Accordingly, a standard called the digital print order format (DPOF) has been made public recently.
According to the DPOF standard, electronic printing information such as the number of prints and trimming is produced and is stored together with image files in the recording medium. Recording formats for recording the image files and the printing information are standardized. In particular, a file (which is called a DPOF file but will hereafter be referred to as a printing information file) for containing the printing information is written in a text file format, and is recorded in the recording medium independently of the image file.
The storage of the printing information and the image files in the recording medium by the digital camera or a related equipment according to the DPOF standard eliminates the necessity of determining numbers of prints to be produced from which images, how the images are trimmed for printing, and the like when the images are printed with the personal printer or at the order to the laboratory for printing. Even if the printer does not have an image regenerating function, desired numbers of prints can be produced from desired images. Moreover, there is no necessity of providing the printer with the image regenerating function.
According to the DPOF standard, the printing information is not added to the image files but is recorded in the text file format as printing information files independently of the image files. This enables the erasure of the image files and the printing information files independently of one another. If the image files are erased freely, the image files may be erased carelessly. In this case, there is such a possibility that the image file designated for printing (which is designated for producing one or more prints) in the printing information does not exist.
To solve this problem, it can be considered that the printing information is corrected at the same time as the erasure of the image file. In this method, however, it is necessary to confirm and correct the printing information every time the image file is erased, and this makes the process of the digital camera difficult and decreases the processing speed of the digital camera.
In another method, whether the image file is designated for printing or not is written in tag information of the image file, and the image file is erased with reference to the tag information without referring to the printing information. This method, however, is ineffective for a camera that has no rules of the use of the tag information. Moreover, the image files as well as the printing information files include the printing information, and the information in the recording medium is redundant.
If the frames are designated for printing only on a frame-by-frame basis in the case where the digital camera has the function of designating frames for printing as described above, it is complicated to designate all frames for printing. Since many users would like one print from each of all frames as is the case with prints with photographic film processing, the users of the digital camera needs to have one print from each of all frames easily as is the case with the prints with photographic film processing.